Control knob



Aug- 14, 1962 R. ABRAMS ETAL Re. 25,224

CONTROL KNOB Original Filed July l2, 1954 llave/ador@ Ra rwm Wrrem EPl/es.

fr@ J Vgmwugvw United States "atet itice 25,224 CONTROL KNOB RalphAbrams, Sharon, Mass., and Warren H. West, Seabrook Beach, N.H.,assignors to Cambridge Thermionic Corporation, Cambridge, Mass., acorporation of Massachusetts Original No. 2,861,825, dated Nov. 25,1958, Ser. No. 442,812, July 12, 1954. Application for reissue May 31,1960, Ser. No. 33,068

8 Claims. (Cl. 287-52.06)

Matter enclosed in heavy brackets appears in the original patent butforms no part of this reissue specilication; matter printed in italicsindicates the additions made by reissue.

The present invention relates to control knobs for attachment to smoothshafts such as are found on electric control panels and similarinstallations.

Control knobs of known types hav-e defects which affect the ease andexactness of connection with a shaft, their adjustment, and thepossibility of dismounting and reseouring the knob to the shaft. Knobswhich are attached by means of set screws or the like become easilyloosened due to the fact that 'the grip about the shaft is not uniform,whereas kno-bs which are attached to shafts with reference to Hats, orsimilar angle-determining provisions, require the shaft to be in adefinite position when the knob is put on.

It is an object of the present invention to provide a control knob whichsecurely, uniformly and symmetrically grips the shaft [knob], to providesuch a knob which can Ibe rotated freely about a shaft prior toattachment and firmly fastened thereto in any index position withoutdisturbing the position yof the shaft, and to provide a control knobwhich can be secured to the shaft with ease and a minimum of effort.

According to the present invention a control knob assembly comprises: asleeve which is longitudinally split at one end for radial resiliency atthat end, which sleeve has a smooth bore throughout its length adaptedto accommodate a shaft, -and which sleeve has an outside rthreaded endportion, the remainder of the outside being smooth; a knob body which onone side engages the smooth portion of the sleeve and which has on theother side an axial recess surrounding the threaded end portion of thesleeve, clearing it with an annular space between sleeve and knob body;a nut which is closed on one side where it has tool engaging means,which nut tits the threaded end portion of the sleeve, and which nut iswith clearance accommodated by the recess of the knob body when engagingthe end portion of the sleeve; and wedging means including taperedsurfaces surrounding the split end of the sleeve, whereby tightening ofthe nut radially compresses the sleeve at this split end to engage theshaft upon relative axial movement of sleeve, nut and wedging means.According to one aspect of the invention, the tapered surfaces are onthe knob body or an inset thereof and on the sleeve whereas, in anotheraspect, these surfaces` are on the nut and on the sleeve.

These and other objects and aspect-s of the invention will appear fromthe herein presented description of two typical embodiments illustratingits novel characteristics. These refer to drawings in which FIG. 1 is atop View of a knob according to the invention;

FIG. 2 is a section through the knob assembly with the shaft to which itis attached in elevation, on lines 2-2 of FIG. 1

FIG. 3 is an exploded sectional view corresponding to FIG. 2;

FIG. 4 is a longitudinal section, simil-ar to FIG. 2, of a secondembodiment of the invention; and

FIG. 5 is a top view of the knob according to FIG. 4, with the cap andnut removed.

The knob assembly shown in FIGS. 1 to 3 has a knob body which consistsof a molded portion 11 of suitable plastic material such as a phenolicresin which contains, molded thereinto, a metal inset 12, for examplemachined from brass stock. The molded porti-on 11 has a shoulder 14 andopens into an inwardly protruding hexagonal rim 15 whose upper -face isush with the outer face of the inset 12. The inset 12 has next to theabove mentioned outer face a tapered portion 17 and between the oppositeface 1S, and the taper 17, an inner annular recess 19 the width of whichis related to a bead of the tapered sleeve. The widened portion of thebore of knob 11, above the face or shoulder 18, forms a space forconfining the upper part of a sleeve 21 and a nut 31, now to bedescribed.

The sleeve 21, machined from metal stock such as brass, has a hexagonalhead portion 22 which lits the hexagonal opening 15 of the knob body,and a taper portion 23 which lifts the taper 17 of the inset 12. Thesleeve 21 has further la cylindrical portion 2'4 with a bead 25, and atthe end' opposite to the hexagonal head 22 it has a threaded portion 26.The sleeve is slotted as indicated at 27, t-o a point between the bead25 and the threaded portion 26, to provide a certain spring action ofthe taper and bead portions. The bead 25 is considerably narrower thanthe yabove described annular recess 19 0f the inset 12.

The closed nut 31 has -a thread 32 that iits the thread 26 of the sleeve21, and a slot 33 for tightening by means of a screwdriver. The nut canbe hexagonal to permit the use of a socket tool.

The cover cap 41 of metal has spring fingers 42, a smooth outer coverportion 43 and a flange 44. Instead, a cap made of resilientnon-conducting material such as rubber or polyethylene can be used, inwhich case the spring ngers can be eliminated.

As particularly indicated in FIG. 3, this knob is used as follows.

For shipment and handling prior to final assembly, the sleeve 21 isinserted into the knob tbody 11 by slight pressure, so that the bead 25comes to lie within the annular recess 19 of the inset 12 thus looselyjoining the two parts. Also for purposes of shipment and storage, thenut 31 can be loosely screwed onto the sleeve 21. In this condition, thehexagonal head 22 of sleeve 21 rests loosely within the hexagonalopening 15 of the knob body 11, with the nut only screwed on far enoughto hold it on the sleeve but not tightened so as to bring the two tapersurfaces 17 and 23 into pressunable contact.

For `attaching the knob to a shaft, such as shown at 50 of FIGS. 2 and3, the sleeve 21 is slipped over the shaft 50, and the nut 31 tightenedby means of a socket wrench or screwdriver, The annular face 34 of thenut 31 is thus pressed against the upper face 18 of the inset 12,thereby lifting the sleeve 21, bringing the two tapered surfaces 17 and23 into contact, compressing the tapered portion of the sleeve 21, andthus pressing the slotted portion of the sleeve against the shaft 50i.It will be noted from FIG. 2 that the shaft is securely held over theenti-re length of the sleeve 21, that the bead 25 is with some clearancecontained within the recess 19, and that the hexagonal head 22 of thesleeve 21 is contained within the hexagonal Vopening 15 of the knob body11, with some clearance between this head and the inset 12, and with thesurface of the hexagonal head 22 well within that opening of the knobbody. The nut 31 is then covered with the cap 41 which ycan be attachedin well known manner to the upper part of the knob, with the springiingers 42 pressurably engaging the cover recess and the flange 44resting against its outer face, as indicated in FIG. 2. In this manner,the metal assembly Within the knob is fully protected and its insulationassured.

A second embodiment of the invention is shown in FIGS. 4 and 5 asfollows.

The knob body 61 is generally speaking similar to the above `describedbody 11, with the exception that it contains molded the-reinto a sleeve71 which has a smooth inner bore 73, a knurled outer surface 74 securingthe inset to the body 61 upon being molded thereinto, and on a shoulder75 a threaded portion 76, which is slotted at 77.

The nut 81 is similar to nut 31 of the first described embodiment, butit has an inside taper 32 which fits an edge or taper 72 of the threadportion 76 of the inset 71.

For assembly, the knob with inset 71 and nut 81 loosely attached isslipped over shaft 50 and the nut 81 tightened by means of a socket orscrewdriver whereupon the tapers 72 and 82 will contact and thencompress the slotted portion of the inset, securing the knob to theshaft. The knob recess can be closed with the cap 41 as described aboveWith reference to FIGS. l to 3.

It will be noted that the shaft is in both instances centered andsecured over the entire length of the inset and that the knob can be puton the shaft in any desired angular position with the above mentionedadvantages of this arrangement. It Iwill -be noted that, in theembodiment according to FlGS. l to 3, the length of the shaft portionwhich protrudes beyond a panel or similar element is not particularlycritical, since the end portion of the shaft will be secured to theslotted portion of the inset even if the end of the shaft is Well withinthat slotted portion.

It should be understood that the present disclosure is =for the purposeof illustration only and that this invention includes all modicationsand equivalents which fall Within the scope of the appended claims.

We claim:

1. A control knob assembly comprising a sleeve which is longitudinallysplit at one end for radial resilience at that end, which has a smoothbore throughout its length adapted to accommodate a shaft, which has anoutside threaded end portion, next to said threaded portion a smoothportion with an annular bead, :and which has at said split end anannular taper next to said smooth portion, and a polygonal head; a knobbody which at one side circularly encompasses said s-mooth portion andsaid taper of said sleeve and polygonally encompasses said head of saidsleeve and has on that side a tapered recess for said taper of saidsleeve and an annular groove for but wider than said bead, and which hason the other side an axial recess surrounding said threaded end portionof said sleeve, clearing it with an annular space between sleeve andknob body; and a nut having tool engaging means, which nut fits saidthreaded end portion of said sleeve and which nut fits with clearancesaid recess of said knob body, when engaging said end portion; whereby,upon tightening of the nut and consequent axial movement between sleeveand knob body, said split end of said sleeve is radially compressed toengage the shaft.

2. A control knob assembly comprising a sleeve which is longitudinallysplit at one end for radial resilience at that end, which has a smoothbore throughout its length adapted to accommodate a shaft, an outsidethreaded end portion opposite to said split end, and a taper and apolygonal head at said split end; a knob body having :an axial borethroughout its length which at one side encompasses said taper or saidsleeve and has on that side a taper iitting said sleeve taper and arecess for engaging said head, `and which has on the other side awidened portion surrounding said threaded end portion of said sleeve,clearing it with an annular space axially open to the outside betweensleeve and knob body and forming a shoulder at the inner enti of saidwidened portion of the bore, and a nut having on one side tool engagingmeans, which nut tits said threaded end portion of said sleeve, bears,at its end opposite to the tool engaging means, against said shoulder ofthe knob body, vand tits Evi/ith clearance said recessg within saidannular space Of said knob body with clearance between nut and knobbody, when engaging said end portion and bearing against said shoulder,said annular space being [higher than] at least substantially as high assaid nut; whereby, upon tightening of the nut and consequent axialmovement between sleeve and knob body, said split end of the sleeve isradially compressed to engage the shaft, and said annular spacecontaining the nut can be closed with cap.

3. A control knob assembly comprising: a sleeve which is longitudinallysplit at one end for radial -resiliency at that end, which has a smoothbore throughout its length adapted to accommodate a shaft, and which hasan outside Ithreaded 4end portion, the remainder of the outside beingsmooth; `a knob body having an axial bore throughlout which on one sideengages sai-d smooth portion of Said sleeve, [and] which has `on theother side an axial recess surrounding said .threaded end portion ofsaid sleeve, `clearing it with an annular space between sleeve and knobbody and which has a transverse foce at the bottom of said crxialrecess; `a nut having tool engaging means and a thread htting saidthreaded end portion of said sleeve and said nut, oppositely to the toolengaging means, benringiagainst said transverse face at the bottom ofsaid aerial recess of the knob body, the outer surface of -said nutbeing with radial clearance accommodated by said recess of said knob and[being] said recess being at least substantially as high as Said nut, sothat said nut is substantially confined therein when engaging said endportion of the Sleeve and bearing against said transverse face of theknob body; and wedging means including tapered surfaces surrounding saidsplit end of said sleeve for radially compressing said sleeve at saidsplit end by tightening said nut; whereby t-he shaft is engaged uponrelative axial movement of sleeve, nut and wedging means and the nut iswhen tightened protected by the knob body against loosening andaccidental disengagement of shaft and knob.

4. A control knob -assembly comprising: a sleeve which has an outsidethreaded end portion iand is longitudinally split -at that end portionfor radial resiliency and which has a smooth bore throughout its length`adapted to accommodate a shaft; a knob body which is on one side#fastened to the other end portion of said sleeve opposite said splitportion and which has on its other -side a recess surrounding andsubstantially extending beyond said threaded end portion of said sleeve,clearing it with an annular space between thread and knob body; and anut having tool engaging means, which nut lits said threaded lendportion of said sleeve is substantially confined in said recess of saidknob body, and which nut has an inside taper at the end yof said threadfor radially compressing said sleeve at said split end upon tighteningof the nut; whereby the shaft is engaged upon relative axial movement ofnut and split end portion of the sleeve and the nut is when tightenedprotected by the knob body against loosening and accidentaldisengagement of shaft and knob.

5. A control knob assembly comprising: a sleeve which is longitudinallysplit at one end for radial resilience at that end, which has an axialsmooth bore adapted to accommodate a shaft, an loutside threaded endportion opposite -to said split end, and a taper and a polygonal head atsaid split end; a knob body which `at one side encompasses said taper ofsaid sleeve, which has on that side la tapered frecess fitting saidtaper and a recess for engaging sai-d polygonal head, and which has onthe other side an axial recess surrounding said threaded end portion ofsaid sleeve, clearing it with an annular space axially open to theoutside between sleeve land knob body, and said knob body having atransverse face intermediare said tapered recess and said axial recess;`and -a nut having on one side tool engaging means, fitting saidthreaded end portion of said sleeve, [and] being substantially contnedin said recess of said knob body when engaging said end portion [and] ofsaid sleeve, and having on the other side a face for engaging said faceof said knob body, such that an outwardly open annular space remains insaid axial recess between the knob body and the nut, and said nut byaxial movement between sleeve -and knob body radially compressing saidsplit end of said sleeve; whereby the shaft is engaged upon relativeaxial movement of nut and split end portion of the sleeve and the nut iswhen tightened protected by the knob body against loosening andaccidental disengagement of shaft and kno-b.

6. A control knob assembly comprising: a sleeve which is longitudinallysplit at one end for radial resilience at that end, which has an axialbore adapted to accommodate a shaft and affording a bearing surface forrotation of the sleeve about the shaft to establish a desired angulau'relation between sleeve and shaft, an outside threaded end portionopposite to said split end, and a taper at said split end; a knob bodywhich at one side encompasses said taper of said sleeve, which has onthat side a tapered recess fitting said tap-er, said sleeve and saidknob body having mating locking portions of noncircular sectional shapelcking the sleeve and knob body against relative rotation whilepermitting relative axial sliding thereof, said knob body having on theother side an axial recess surrounding said threaded end portion of saidsleeve, clearing it with an annular space axially open to the outsidebetween sleeve and knob body, and said knob body having a transverseface intermediate said tapered recess and said axial recess; and a nuthaving on one side tool engaging means, fitting said threaded endportion of said sleeve, being substantially wholly confined within saidaxial recess of said knob body when engaging said end portion of saidsleeve, and having on the other side a face for engaging said face ofsaid knob body, such that an outwardly open annular space remains insaid axial recess between the knob body and the nut, and said nut byaxial movement between sleeve and knob body radially compressing saidsplit end' of said sleeve; whereby the shaft is engaged upon relativeaxial movement of nut and split end portion of the sleeve and the nut iswhen tightened protected by the-knob body against loosening andaccidenatl disengagement of shaft and knob.

7. A control knob assembly comprising: a sleeve which is longitudinallysplit at one end for radial resilience at that end, which has an axialbo-re adapted to accommodate a shaft and affording a bearing surface forrotation of the sleeve about the shaft to establish a desired angularrelation between sleeve and shaft, an outside threaded end portionopposite to said split end, and a taper and a polygonal head at saidsplit end; a knob body which at one side encompasses said taper of saidsleeve, which has on that side a tapered recess tting said taper, and arecess for engaging said polygonal head, and which has on the other sidean axial recess surrounding said threaded end portion of said sleeve,clearing it with an annular space axially open to the outside betweensleeve and knob body, and said knob body having a transverse faceintermediate said tapered recess and said axial recess; and a nut havingon one side tool engaging means, ytting said threaded end portion ofsaid sleeve, being substantiall; wholly confined within said axialrecess of said knob bod; when engaging said end portion of said sleeve,and hav ing on the other side a face for engaging said face of sait knobbody, such that an outwardly open annular spac| remains in said axialrecess between the knob body am the nut, and said nut by axial movementbetween sleevl and knob body radially compressing said split end 0 saidsleeve; whereby the shaft is engaged upon relativ` axial movement of nutand split end portion of the sleev` and the nut is when tightenedprotected by the knob bod, against loosening and accidentaldisengagement of shaf and knob.

8. A control knob assembly comprising: a sleeve whic. is longitudinallysplit at one end for radial resilience a that end, which has an axialsmooth bore adapted to ac commodate a shaft and affording a bearingsurface fo rotation of the sleeve about the shaft to establish a desired angular relation between sleeve and shaft, an outsid threaded endportion opposite to said split end, and taper at said split end; a knobbody which at one sid encompasses said taper of said sleeve, which as ontht side a tapered recess fitting said taper, said sleeve an said knobbody having mating locking portions of nor circular sectional shapelocking the sleeve and knob bod against relative rotation whilepermitting relative axiz sliding thereof, said knob body having on theother sia an axial recess surrounding said threaded end portion c saidsleeve, clearing it with an annular space axially ope to the outsidebetween sleeve and knob body, and sai knob body having a transverse faceintermediate sai tapered recess and said axial recess; and a nut havingo `one side tool engaging means, fitting said threaded en portion ofsaid sleeve, being substantially wholly confine within said axial recessof said knob body when engagin said end portion of said sleeve, andhaving on the oth: side a face for engaging said face of said knob bod;such that an outwardly open annular space remains i said axail recessbetween the knob body and the nut, an said nut by axial movement betweensleeve and knob boa radially compressing said split end of said sleeve;wherel the shaft is engaged upon relative axial movement of n1 and splitend portion of the sleeve and the nut is whe tightened protected by theknob body against loosenir and accidental disengagement of shaft andknob.

References Cited in Jthe le of this patent or the original patent UNITEDSTATES PATENTS 1,420,295 Tait June 20, 192 1,563,635 Kash Dee. 1, 19S1,787,105 Delaney Dee. 30, 19E 2,151,831 'Buccicone Mar. 28, 19E2,256,419 Tinnerrnan Sept. 16, 19L 2,719,047 Bayes et al Sept. 27, 1912,801,119 Paul-Huhne July 30, 191 FOREIGN PATENTS 423,047 Great BritainIan. 24, 19 586,470 Great Britain Mar. 17, 19l 790,205 Gre-at BritainFeb. 5, 19.' 497,027 Great Britain Dec. 12, 192 890,093 France Oct. 25,19A

